Slide bead coating with a low viscosity carrier layer

摘要

An improved method of thin film coating is taught that uses a multi-slot coating apparatus to apply multiple liquid layers to a moving substrate. The lowermost layer contacting the substrate is comprised of an organic solvent. The lowermost layer may be a single organic solvent or a blend of several organic solvents. Whether comprised of a single organic solvent or a blend of organic solvents, the viscosity of the lowermost layer is less than 1 cp and the wet thickness of the lowermost layer is not more than about 5 mum. Additional liquid layers are applied to the moving substrate on the top of the lowermost layer. This method allows for application of coatings at high substrate speeds. This method also allows for the reduction of coating artifacts caused by contamination of the surface of the die.